How to nail your Y Combinator application (for deeptech)

How to get into YC as a deeptech company

"We accept approximately 200 out of 20,000 applications every batch, ie the top 1%, and most teams we accept have no revenue at all." — Tom Blomfield, YC Partner (Source)

If you want 100+ VCs clambering to meet with you, multiple competing term sheets, and a valuation you could only dream of, then we must admit that Y Combinator remains very useful at doing just that. Top-tier AI and deeptech companies in recent YC batches are raising seed rounds at $40M to $100M+ valuations. And despite how it might seem, YC is not only AI wrappers. If you’re building hardware, there’s never been a better time to apply to YC with 10-15% of companies in this category, up from 3-5% a decade ago.

We hope you agree this is the best-ever guide to nailing your YC application. I’m going to outline how to make yours stand out from the 100,000 applications they get each batch. 

I myself have been accepted into YC, and my YC startup Demand Curve became the go-to growth agency for other YC startups for years. I’ve worked with over a hundred YC startups on growth advising, and evaluated thousands through my deeptech seed fund, Julian.capital. I know what VCs are looking for when they’re evaluating startups.

It’s probably not what you think.

By the way, if you’re going through the full process of applying to YC, you may as well apply to a bunch of other great programs like DeepChecks.vc (the best!), a16z’s speedrun, Discipulus, IndieBio, HAX, CDL, and Hf0, to name a few.

YC reviewers

Let’s start by getting into the mindset of reviewers. 

Historically, YC has shown they’re able to produce ~2 unicorns per batch (companies worth $1 billion or more). 

YC invests ~$75M per batch and targets a 10x return. But after accounting for how much their stake gets diluted through future fundraising rounds, those 2 unicorns per batch need to generate around $25 billion in combined value. Translation: only decacorns ($10B+ companies) really matter to YC's returns.

So, what does it take to build a decacorn?

Every VC has a different formula for what they think it takes, but for YC, it’s pretty clear:

1. To-be-massive, growing market
2. Novel insight
3. Incredible founders who are relentless and resourceful

Let’s begin.

To-be-massive, growing market

Not every good idea can even become a decacorn—even if executed brilliantly. 

If only $100 million worth of a certain kind of widget are purchased each year, and you’re going to build a better widget, then there’s just no reasonable path to becoming a decacorn.

That being said, a promising market does not necessarily mean that the market is already fully established! For example, if your widget is 10x cheaper, and accordingly expands the number of customers that can afford it by 1,000-fold, then the market can be big enough thanks to your innovation. If that’s the case, you need to spell out how that can happen step-by-step.

For Airbnb, as one example, there was not much of a market for room-sharing when they started. However, they pulled customer interest away from the $1 trillion hotel market, and offered all kinds of new perks and places at lower prices—growing the market in the process. Similarly, when Uber started, few were hitchhiking, but Uber rode the explosive growth of the smartphone market to create a new ride-hailing category that pulled from taxis and expanded the total market dramatically.

The point is that markets don’t have to be big now. But they have to be massive in the future, and you must be able to convincingly explain why. 

And if you’re first to the new market, you can get a multi-year headstart and dominate the wave you create and/or ride. Make this clear. (We’ll show how soon.)

To repeat: YC stresses the importance of fast-growing markets above all.

In fact, they prefer small markets with extremely fast growth rates—like those fueled by new technology shifts (AI, mobile adoption, or regulatory changes)—over large, stagnant, existing markets. They’ve looked at their data: YC’s biggest winners often start in niches but explode by redefining or monopolizing their segment.

When Coinbase founder Brian Armstrong got into YC in the Summer of 2012, the market for crypto wallets was tiny—only 100,000 wallets globally. He was able to clearly articulate the complexity and fear associated with hosting a wallet and safely storing the public and private keys. His entire YC thesis was: building a "clean, well-lit place" (essentially a browser) for people to interact with the blockchain, would turn a promising yet relatively non-existent market into one of the fastest growing markets in history.

Novel insight

If there first necessary ingredient in your application is how big you can be, the second is how your idea is powered by a novel insight.

You should explain how something recently changed about the world that only now makes your startup’s pursuit of this market even possible. 

A 2x better feature or design is not enough. That’s not a novel insight. No, you need a non-obvious truth about the problem that people have missed until now. One that you’ve uncovered through experience, data, or sheer obsession. One that is now only possible due to market, technological, regulatory, or consumer sentiment shifts.

If it was possible for a long time, then others would have pursued it successfully by now. But they didn’t, because it’s not actually a good idea. That’s why the why now matters to keen investors.

Many startups tried to build Uber before them, but it was the combination of ubiquitous smartphone use with great GPS signals and the aftermath of the great financial crisis that left people looking for gig work. The taxi experience had also just hit an all-time low, with taxi monopolies treating customers unfairly and squeezing them for maximum prices.

Re-read that for a second. Your application should read like a series of “aha” moments, each building toward why your market will be massive and why you will dominate it.  After you blow the reviewer’s mind with the future, inevitable size of the opportunity, the next question they’ll have is “well if the opportunity is so great, why hasn’t someone gotten a headstart here yet?

The story of how you came across this insight is just as important as what the insight is—because it reveals how your life has been leading up to this pursuit. Investors want to hear this because they want you to relentlessly pursue this idea as if it’s the last thing you’ll ever work on. They need to believe this is your mission. Because without it, you’re going to quit when things get tough. And they will.

In your application, spell it out plainly: “We discovered X by relentlessly doing Y, which means we’ve discovered Z opportunity that nobody else sees.”

Incredible founders who are relentless and resourceful

Many people have good ideas, but very few act on them or are even capable of doing so. The third ingredient is explaining how you’ve assembled the perfect and highly motivated team.

For VCs, often the best predictor of future success is past success. That doesn’t mean you founded a great startup, but that at least your life has shown signs of serious  accomplishment. In your application, point to the truly great things that your founding team has built. Show off how you’ve been relentless and resourceful in past projects—they don’t have to be startups. Given there is limited time and information available to assess founders, VCs must look at anything that you create as a proxy for how well you’ll build a company. They index on this! What separates a great startup idea that two founders identically share? Which founder is more capable. You’re not only pitching your idea; you’re also pitching your hustle

The second best indicator of future success—beyond past success—is how fast you’re moving now. Speed is everything in startups, and YC pushes this more than almost anyone. It’s in their mantra. So, in your application, tell the story of what actions you took to move as fast as possible without cutting existential corners. Whether it’s building something impressive quickly, or getting rapid traction with customers—show your hustle and speed. The best companies tend to grow the fastest, and to grow the fastest, you generally have to iterate and build the fastest. Seems obvious, right? But most people move painfully slow. So explain how you’ve moved fast.

Now that you know what reviewers are looking for at the highest level, we need to weave these learnings into the questions that are actually asked on the YC application. We got you, let’s dive through that.

First, it’s worth noting that not all companies need YC program. If you’re ready to raise a pre-seed or seed round right now, you should submit an application to DeepChecks.vc and get your fundraise started. It only takes a minute, unlike the length of a YC application, and we’re specifically designed to identify high potential deeptech ideas across all the niche sectors we’ve encountered over the past 2 years. You’ll then be matched with all of the deeptech VCs that invest in your stage and sector. You could get 40 meetings in a day—happens all the time. We are the biggest funding platform for deeptech. And it’s free.

Now, back to the YC application.

Before we go through each question in detail, it’s important you are capable of writing clear and concise answers. Here are a few examples of Do’s and Don’ts when writing your YC application.

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YC Application Form Questions

1. Who writes code, or does other technical work on your product? Was any of it done by a non-founder? Please explain.

This is a screening question. YC explicitly advises that for most businesses, success requires a technical co-founder who can handle building the product internally. Outsourcing is seen as a workaround that often signals the founders lack the ability to execute on their idea independently or recruit a co-founder with the appropriate capabilities.

If you don’t have technical expertise in-house, go recruit the best person in the world to build with you first and then come back and apply to YC.

If you’re already the best founding team in the world to build this company then this is your opportunity to tell that part of the story. Also use this question to tell the story of how you know each other and how well you work together.

2. Are you looking for a cofounder?

This is another screening question. YC primarily looks to back complete, committed founding teams, as they view team strength as the top evaluation criterion—strong teams can pivot ideas successfully. While they tend to prefer co-founders, they do accept solo founders (about 10-20% of batches), but solos must demonstrate exceptional capability and often address co-founder recruitment plans in applications. If you’re a solo founder, this is your chance to outline who you’re recruiting and why it hasn’t already happened without sounding like you’re incompetent nor lazy.

3. Founder Video

This is an opportunity to sound sharp, obsessed, and persuasive. Massive bonus points if you show off your storytelling skills. Make sure you’re addressing the promising market opportunity and the novel insight that you’re founding this company on—as we discussed in the opening of this guide—as that’s what makes your success feel inevitable.

Don’t use a script, don’t use background music, and ensure the lighting is on your face. They want to see your personality, not your editing skills.

Examples:

• Doordash (S13)
• Zenefits (W13)
• Teespring (W13)
• Embark Trucks (W16)
• Podpal (S24)

4. Describe what your company does in 50 characters or less.

This is a test of two things. First, your ability to be concise, and second, how well you understand your own opportunity.

Write a full long-form memo describing what your company does, the market opportunity, and the novel insight. Then compress that memo into a one-pager, then a paragraph and then a 50 character sentence. Consider an LLM to help you compress.

If half of your effort goes into the founder video and this elevator pitch, the rest of the application will fall nicely into place because it’s anchored on an immediately clear pitch.

Examples:

Nest - The thermostat that learns.

Boom Supersonic - Travel at twice the speed of sound.

SpaceX - Making humanity multi-planetary.

Anduril - The operating system for defense.

Square - Accept credit cards with your phone.

Aalo - Factory-built nuclear to power AI data centers.

5. Demo Video

Your demo should make the value that you’re providing customers immediately intuitive, and is one of your top chances to be memorable and manufacture those “aha moments” for reviewers.

Examples:

• Dropbox (S07)
  
  
• Tornyol (F25)
  
  
• Reflect Orbital

6. What is your company going to make? Please describe your product and what it does or will do.

This is an opportunity to show off your attention to detail—how you navigate what customers need and how you provide it brilliantly—and weave in some of the important information that you won’t necessarily get asked about explicitly.

Particularly, the YC application doesn’t explicitly ask about the market opportunity. So, while you’re directly answering the question that you’ve been asked, make sure to also describe how your product is directly addressing a rapidly growing market need.

Examples:

Uber: Everyone’s Private Driver (2009)

• UberCab is a membership-based service which allows you to request a car via SMS or iPhone app. It provides a 'Private Driver' experience that is 1.5x the price of a cab, but arrives in under 5 minutes. We use GPS to coordinate the closest driver with the user, ensuring the car is never more than a few blocks away. By filling the 50% 'dead time' of professional black car drivers, we provide luxury service at a fraction of the traditional cost.

Coinbase: The "Browser for Bitcoin" (2012)

• Coinbase is the easiest way for a person to buy, send, and receive Bitcoin. Currently, using Bitcoin requires technical knowledge of 'private keys' and 'nodes.' We are building the 'browser' for the Bitcoin network—a hosted wallet that allows any consumer to link their bank account and exchange US Dollars for digital currency in one click. We abstract away the complexity of the blockchain into a simple, consumer-friendly interface that looks and feels like PayPal, but runs on a decentralized protocol.

GoPro: "The World’s Most Versatile Camera" (2004)

• GoPro is a wearable camera system designed to capture professional-quality video from the center of the action. By combining a wide-angle lens with a rugged, shockproof, and waterproof housing that can be strapped to the wrist, chest, or helmet, we enable athletes and explorers to document their experiences from a first-person perspective. It is more than a camera; it is a tool that turns your life into a movie, allowing you to 'Be a Hero' without needing a film crew.

Oculus Rift: "Step Into the Game" (2012)

• The Oculus Rift is the first truly immersive virtual reality headset for video games. By using custom optics and ultra-low latency head-tracking, we provide a field of view that is more than double that of previous VR attempts. When you put on the Rift, you no longer feel like you are looking at a screen; the 3D imagery fills your entire vision, and the world moves with your head in real-time. We have solved the 'motion sickness' problem of the past to create a sense of 'presence' that makes your brain believe you are actually inside the digital world.

7. Explain your decision regarding location.

Not every company needs to be built in San Francisco, but every great founding team should actively choose where to build the company based on things like talent availability, customer proximity, access to grants, warehouse space, suppliers or critical partners. Your location decision should sound strategic, not happenstance. In fact, everything you do should sound strategic. You’re an intentional entrepreneur, not a YOLO’er.

8. How far along are you?

This question and the next one are to illustrate how incredibly fast you’re moving. Make sure you tell a compelling story about lightning speed execution and a tremendous level of commitment. For this to be effective, it must come across as top 1% compared to other applications: these founders know how to cut past the BS, run experiments quickly, get answers quickly, and point themselves in the right direction.

For example, Deel famously interviewed 600 customers in 6 weeks during YC to pivot their product from something that wasn’t working, to the sub-contractor/employer of record product that made them the fastest growing SaaS company of all time (at the time). They later coined the term “Deel Speed”, which manifested into everything they do at the company and has been was baked into the company DNA from the beginning.

9. Are people using your product?

YC cares a lot about traction. Proving that customers are using your product shows that you’re not delusional about demand and that you are competent in execution. And demand, ultimately, is everything. Further, if you’re stating everyone wants your product and that it’s ready but you haven’t yet proved it, you’ll look lazy and slow. You should want to be certain of your direction so you know for your own sake you’re not wasting your time.

If you don’t have users yet, then use this question as an opportunity to describe all of the market research and customer discovery that has led to your unique insight. How are you absolutely positive people want this?

10. Do you have revenue?

There’s no better signal that your product is actually what the market wants than customers paying for it. However, not all companies can collect revenue so soon, especially hardware companies. There are ways for you to show traction without revenue. One option is with signed LOIs from potential customers (read our guide on LOIs here).

11. If you are applying with the same idea as a previous batch, did anything change? If you applied with a different idea, why did you pivot and what did you learn from the last idea?

If you’ve previously applied to YC, you’ll want to use this question to illustrate the speed that you’re moving and iterating on your business. If not much has changed since your last application, you’ll surely be rejected. If you’ve had any earth shattering new insights, share them here.

12. If you have already participated or committed to participate in an incubator, "accelerator" or "pre-accelerator" program, please tell us about it.

This is another screening question. YC has funded companies that have already participated in another program, but they expect a higher bar for progress and traction since the startup has already benefited from additional resources—failure to show substantial advancement can be a red flag.

YC requires full-time commitment during the batch, making overlapping participation logistically challenging. You can and definitely should apply to multiple accelerators simultaneously, but active involvement in another during YC isn't supported.

13. Why did you pick this idea to work on? Do you have domain expertise in this area? How do you know people need what you're making?

This is an opportunity to make sure you’ve drilled home three very important things:

1. You’ve deeply explored all the permutations of your idea and how it interacts with its market, customers, and technology. This is called “exploring the idea maze.” You’re intentional, not a YOLO’er.
2. Founder-market fit—you are the best person in the world to pursue this startup. 
3. The effort you’ve already put in to discover your insight—you are absolutely obsessed.

14. Who are your competitors? What do you understand about your business that they don't?

Building on the previous answer—where you illustrate how you’ve explored the idea maze of ideas to work on—this answer should illustrate how you’ve explored the idea maze of other approaches and why they’re all inferior to yours. 

A great example is the founder of Zoom, Eric Yuan, who spent 14 years at WebEx becoming a domain expert before realizing the market leaders were failing their customers. Despite being told the space was "saturated," he bet that the incumbents were vulnerable to a simpler, higher-quality alternative.

By focusing on frictionless distribution (no accounts needed, incredibly simple setup, freemium pricing), universal compatibility (Mac, Windows, iOS, Android), and a "video-first" architecture that worked on any connection, he proved that "good enough" wasn't enough. While giants like Cisco and Microsoft focused on enterprise features, Eric won by obsessing over a product that actually worked and sounded good every time.

15. How do you (or will you) make money? How much could you make?

Use this answer to describe the bottom up calculation of how much the market opportunity is. Start from your business model, building into who the customers are today and who they will be over time, how your services will evolve and finally the total addressable market for your business. Building it up clearly in this way is far more effective than pulling a number from a research report that’s totally irrelevant to the business you’re building.

Answering this thoughtfully shows you’re interested in building a massive business. And, as we opened with, that’s the whole point of YC.

Uber, for example, said that they were starting with a more convenient, on-demand, premium black car service that costs $100/ride on average, with a 15% take rate. There are currently 1M of these rides per year in San Francisco and once they capture 1% of them ($1M GMV/year) they will expand to 3 more cities. Once they reach $10M GMV/year across multiple markets, they’ll layer on UberX for cheaper (~$25) and far higher volume rides (10M/city). After 10 years, they will expand the ride-hailing market dramatically, scaling into 10,000+ cities doing 7B rides per year, handling $65B in GMV and earning $14B in revenue.

Conclusion

Once you’ve written your entire application, re-read this article from top to bottom and make sure that you’re not missing the key ingredients. Then rewrite your application until it’s incredibly concise—making it impossible to get bored while reading it. Concision is half the battle. 

If you don’t get into YC, no fear, it’s not important. Much lighter-touch funding platforms exist like DeepChecks.vc if you’re a deeptech company, or a16z’s speedrun and Hf0.